Toggle mechanism



Jan. 20, 1970 F, GUSTAVSON TOGGLE MECHANISM 2 Sheets-Sheet 1 Filed Sept. 27, 1967 INVENTOR 'FREDRJK G USTAVSON ATTYS.

Jan. 20, 1970 F. GUSTAVSON TOGGLE MECHANISM 2 Sheets-Sheet ,2

Filed Sept. 27, 1967 INVENTOR ATTYS,

United States Patent U.S. Cl. 74520 4 Claims ABSTRACT OF THE DISCLOSURE A toggle mechanism in which the toggle action is controlled by a spring link coupled to a rotatable operating shaft and to a rotatable link plate so as to be compressed and released during initial and final parts of the toggle action; the operating shaft carries a slotted plate and a link system is coupled between the slotted plate and the link plate such that a dead centre position is reached before maximum compression of the spring in the link. Accordingly, there is no equilibrium position and the toggle mechanism cannot stick in a true dead centre position.

The invention relates to toggle mechanisms. Such mechanisms, which may be operated manually, are particularly useful in electrical switch gear where a positive drive to one of two switch positions is desirable and in similar applications.

The object of the present invention is to provide a simple and yet versatile toggle mechanism.

One embodiment of the invention will be more particularly described hereinafter with reference to the accompanying drawings in which:

FIGURE 1 illustrates a toggle mechanism in one of its end positions; and

FIGURE 2 illustrates the toggle mechanism in its other end positioni.e. the element moved by the mechanism is in its other end position.

Referring to FIGURES 1 and 2; an element is required to move with a toggle action between two end positions; the two end positions may correspond to the two positions of a switch or the movement of the element 10 may be positively transmitted to operate the switch.

An operating shaft 11 on which is shown a handle 12 has rigidly mounted on it a plate 13 having an anchor pin 14. The pin 14 extends through slots 15 in the rigid cylindrical tube 16, and forms a movable anchor pin for the spring 17 which is anchored to the tube 16 at its other end by the fixed anchor pin 18. The pin 18 also constitutes the other wearing end connection for the tube 16, being mounted on a link plate 19 constituting a crank. The link plate 19 is rotatable about the fixed pin 20 and transmits movement via pin 22 to the arm 21 which is integral with element 10. Rotation of the shaft 11 compresses the spring 17 which releases abruptly after dead centre is reached; consequently, the element 10 is movable with an overcentre toggle action from one end position to the other. FIGURE 1 shows one end position and FIGURE 2 shows the other end position. The element 10 is slidable between its two end positions, pins 44 and 45 on plate 54 engaging slots 46 and 47 in element 10.

The plate 13 has two slot end abutment 23, 24 disposed at a fixed distance from one another; in the embodiment shown in FIGURES 1 and 2 the abutments 23 and 24 are sides at opposite ends of a slot 25. Clockwise rotation of the shaft 11 in FIGURE 1 causes slot 25 to slide along pin 26 of link bar 27 until end 24 bears on the pin 26; further rotation causes the link bar 27 to move to the position shown in FIGURE 2. The reverse rotation moves the bar 27 back to its initial position. The bar 27 is pinned by pins 28 and 29 to links 30 and 31 3,490,309 Patented Jan. 20, 1970 which are themselves pinner by pins 32. and 33 to element 10. The pins 28 and 29 are slidable in the arcuate slots 134 and 135 in the support plate 54, which also acts as a rigid support for the fixed pivots and shafts of the mechanism. The bar 27 can thus move the element even if spring 17 fails.

When the shaft 11 and therefore the plate 13 are rotated so that the anchor pins 14, 18 of the spring 17 form a straight line with the shaft 11, the spring 17 is at maximum compression. Further rotation of the plate 13 beyond this position allows the spring to expand and cause the element 10 via the link plate 19, to snap into its other end position and complete its toggle action. To ensure that there is no chance of the shaft 11 and therefore the plate 13 sticking or easily balancing in the in line position reached when the anchor pins 14, 18 form a straight line with the shaft 11, the abutments 23 and 24 of the arcuate slots 25 are adapted to start to push the link bar 27 when shaft 11 is between 2 and 5 before its angular position at dead centre of the toggle movement. Upon further rotation of the shaft 11, the bar 27 pushes the links 30 and 31 out of their respective locking positions and acts on the element 10 with less movement and in the same direction as the toggle movement initiated by the spring. The link plate 19 turns in the opposite direction to the shaft 11 and so the anchor pin 18 tends to meet the other anchor pin 14 so that the anchor pins and the shaft 11 lie on a straight line formed a few degrees of rotation before that angular position of the shaft 11 which, with the same mechanism dimensions, would have given the in-line position.

An analogous operation occurs when the mechanism is operated in the reverse direction.

At the position when one of the slot-end-abutments 23 or 24 bears against pin '26; the corresponding end 35 or 36 of arcuate slot 37 bears against pin 38 on link 39, which is pivoted at the pin 40 to link 41, itself pivotally attached to link plate 19 at the pin 42. The pin 40 is slidable in arcuate slot 43 in plate 54. This arrangement transmits the further rotation of shaft 11 to link plate 19 to ensure that the link plate 19 does not stay in the dead centre position.

The mechanism described above ing conditions, namely:

(a) A single operating spring assists a toggle movement 1n two opposite directions;

(b? The operating shaft cannot be balanced so as to remam in a position corresponding to the unstable position of the operating spring-Le. where the spring is at maximum compression: the position of the operating shaft therefore gives an accurate indication of the position of the element;

(c) The element 10 can be mechanically locked in one of its end positions by the links 30, 31;

Two further important requirements are:

(d) The toggle movements cannot be retarded by the operating shaft; and

(e) The element 10 can always be brought to one or the other of its end positions by rotation of the operating shaft even if the operating spring or its associated links are missing owing to spring breakage or the like.

To meet these two latter requirements, the abutments 23, 24 (and abutments 35 and 36) must be in such an angular relationship to one another that before the bar 27 starts to be moved, which is before the spring reaches its position of maximum compression, the abutments must be so positioned as to act on the bar 27 even when the mechanism is in its two end positions. Consequently, the element 10 may then be moved between its two end positions without the operation of the spring 17. Of course,

this movement without the spring 17 is not a toggle action.

fulfills certain operat- The distances between the abutments 23 and 24 and between abutments 35 and 36 in the plate 13 are, in relation to the other dimensions of the mechanism, arranged so that, when the anchor pins 14, 18 are on a straight line with the shaft 11, the mechanism can snap into its other end position, even though shaft 11 and the plate 13 be forcibly retained in the position associated with the beginning of the toggle movement.

The mechanism described above has the additional useful feature that less than 90 of rotation of shaft 11 is required to operate it.

I claim: a

1. A toggle mechanism comprising an element movable between two end positions; ;a drive member rigidly mounted on a rotatable operating shaft and slidably engaging one end of a spring linkage; an operating link constituting a crank which is pivotally coupled to the spring link and is movable between two end positions, the element being coupled to the crank, the pivot point of the brank being separatefrom the operating shaft wherein rotation transmitted from the operating shaft to the drive member is transmitted to the crank via the spring link, and further comprising linking means coupled in parallel with the spring linkand arranged, during some of the movement against the spring action of the spring link, to tend to turn the crank in the opposite direction in relation to the drive member, and during the releasing movement only of the spring link, to be released from driving engagement with the drive member.

2. A mechanism as set forth in claim 1, wherein said linking means comprises an intermediate link carrying pivotally mounted locking links pivotally mounted at their other ends to said element, which is slidable between its two end positions, said intermediate link being moved by engagement with one of two slot end abutments of said drive member.

3. A mechanism as set forth in claim 2, wherein said slot and abutments are spaced angularly on said drive member so that in the two end positions a portion of said intermediate link rests against a respective slot end abutment of said drive member which is moved to cause the turning of said crank by the other slot end abutment.

4. A mechanism as set torth in claim 3, wherein said intermediate link moves along an arcuate path and said element, locking link and intermediate link form a locking arrangement when said element is in one end position, there being provided a further intermediate link, a fixed member defining an arcuate slot, said further intermediate link engaging said arcuate slot and being pivotally coupled to the crank to form thereby a locking arrangement for the other end position ofthe element.

References Cited UNITED STATES PATENTS 1,366,360 1/1921 Clouse 74-38 X 1,518,701 12/1924 Penn 74-400 X 2,027,735 1/1936 Klocke 74-40 3,212,346 10/1965 Bachman 74100 FRED C. MATTERN, JR., Primary Examiner C. F. GREEN, Assistant Examiner U.S. Cl. X.R. 74-100 

